Camshaft adjusters of this class are used for changing the relative angular position of the camshaft relative to the crankshaft of an internal combustion engine. Here, the adjusting device comprises a drive element that is driven by the crankshaft via a gear and is supported so that it can rotate relative to the camshaft, wherein at least two hydraulic chambers are formed between the drive element and the camshaft and these hydraulic chambers can be pressurized with a pressurized fluid, in order to set a defined relative rotational position between the drive element and the camshaft.
The pressurized fluid is controlled with hydraulic valves. For central valve systems, an actuator in the form of a central magnet is mounted coaxial to the camshaft by a flange separated from the associated hydraulic system in a position-fixed structure of the motor (housing element, e.g., the timing gear cover). Current is fed into a coil of the electromagnet by a connector. The magnetic field induced in this way is transmitted to a moving magnetic armature via a soft iron core consisting of a yoke, yoke plate, magnetic housing, and pole core. It exerts a magnetic force on the armature in the direction of the gap reduction across a working air gap between the pole core and the armature. This magnetic force is transmitted to a piston of the central valve via a pressure pin. The volume flow of the pressurized fluid to the camshaft adjuster is changed by the displacement of the piston.
The actuator of the camshaft adjuster is attached to the housing element in the prior art usually by a screw connection. Such solutions are disclosed, for example, in DE 102 11 467 A1, DE 10 2007 019 923 A1, and DE 10 2006 031 517 A1.
A screw-less fastening of the actuator on the housing element has also become known, as mentioned in passing in DE 102 52 431 A1. A bayonet mount can be used here to fix the actuator on the housing element. In this case, the actuator that is to be mounted concentric to the axis of the camshaft adjuster is mounted by a rotational movement after which it is inserted into a corresponding handle section of the bayonet mount.
A disadvantage in this procedure is that it sometimes difficult for the installer to perform the rotational or pivoting movement, because this must be performed with a certain, not insignificant torque produced by the requirement for a fixed seating of the actuator in the installed state and the required fitting tolerances between the actuator and housing element.